ABI40 Image Data Processing
IODP-MSP drilling and logging contractor: ESO
Hole: M0007B
Expedition: 310
Location:
Latitude: 17° 45.9462' S
Longitude: 149° 33.0682' W
Logging date: October 16, 2005
Sea floor depth (driller's): 56.16 mbrf (41.65 mbsl)
Sea floor depth (logger's): 56.16 mbrf
Total penetration: 47.93 mbsf
Total core recovered: 27.02 m (56.37 % of cored section)
Oldest sediment recovered: Pleistocene sequence
Lithologies: Reef framework, algal crusts, and microbialite matrix
ABI40: 24.75-31.15 mbsf
The ABI40 acquired acoustic images at millimetre scale resolution. The images show the acoustic hardness of the lithologies within the coral reef sequence with a pixel size of 1.1 mm horizontally by 4 mm vertically.
The images are displayed as an unwrapped borehole cylinder and are provided in .BMP and .PDF format. A dipping plane in the borehole will appear as a sinusoid on the image with the amplitude of this sinusoid proportional to the dip of the plane. The images are oriented with respect to north, hence the strike of dipping features can also be determined. Additional processing on the accelerometer data of the image tools by a double integration of the acceleration allowed, whenever needed, a detailed repositioning of the recorded image data to its correct position with respect to the seafloor.
The ABI40 images of the borehole wall are unaffected by borehole fluid quality.
In hole M0007B, the ABI images are of good quality throughout the logged section, although due to hostile borehole conditions it was only possible to acquire images over a short (< 7 m) interval.
Additional information about the drilling and logging operations can be found in the Operations section of the Site Chapter in IODP Proceedings of Expedition 310.
For further questions about the data, please contact:
Jennifer Inwood
Phone: 011-44-116-252-3327
Fax: 011-44--116-252-3918
E-mail: iodp@le.ac.uk